#include <AK/Assertions.h>
#include <AK/Types.h>
#include <Kernel/Arch/i386/CPU.h>
#include <Kernel/Arch/i386/PIC.h>
#include <Kernel/Devices/KeyboardDevice.h>
#include <Kernel/TTY/VirtualConsole.h>
#include <Kernel/IO.h>

//#define KEYBOARD_DEBUG

#define IRQ_KEYBOARD 1
#define I8042_BUFFER 0x60
#define I8042_STATUS 0x64
#define I8042_ACK 0xFA
#define I8042_BUFFER_FULL 0x01
#define I8042_WHICH_BUFFER 0x20
#define I8042_MOUSE_BUFFER 0x20
#define I8042_KEYBOARD_BUFFER 0x00

static char map[0x80] = {
    0, '\033', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', 0x08, '\t',
    'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n', 0,
    'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', '\'', '`', 0, '\\',
    'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/',
    0, 0, 0, ' ', 0, 0,
    //60
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    //70
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    //80
    0, 0, 0, 0, 0, 0, '\\', 0, 0, 0,
};

static char shift_map[0x80] = {
    0, '\033', '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+', 0x08, '\t',
    'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', '\n', 0,
    'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '"', '~', 0, '|',
    'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', '>', '?',
    0, 0, 0, ' ', 0, 0,
    //60
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    //70
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    //80
    0, 0, 0, 0, 0, 0, '|', 0, 0, 0,
};

static KeyCode unshifted_key_map[0x80] = {
    Key_Invalid,
    Key_Escape,
    Key_1,
    Key_2,
    Key_3,
    Key_4,
    Key_5,
    Key_6,
    Key_7,
    Key_8,
    Key_9,
    Key_0,
    Key_Minus,
    Key_Equal,
    Key_Backspace,
    Key_Tab, //15
    Key_Q,
    Key_W,
    Key_E,
    Key_R,
    Key_T,
    Key_Y,
    Key_U,
    Key_I,
    Key_O,
    Key_P,
    Key_LeftBracket,
    Key_RightBracket,
    Key_Return,  // 28
    Key_Control, // 29
    Key_A,
    Key_S,
    Key_D,
    Key_F,
    Key_G,
    Key_H,
    Key_J,
    Key_K,
    Key_L,
    Key_Semicolon,
    Key_Apostrophe,
    Key_Backtick,
    Key_LeftShift, // 42
    Key_Backslash,
    Key_Z,
    Key_X,
    Key_C,
    Key_V,
    Key_B,
    Key_N,
    Key_M,
    Key_Comma,
    Key_Period,
    Key_Slash,
    Key_RightShift, // 54
    Key_Invalid,
    Key_Alt,     // 56
    Key_Space,   // 57
    Key_Invalid, // 58
    Key_F1,
    Key_F2,
    Key_F3,
    Key_F4,
    Key_F5,
    Key_F6,
    Key_F7,
    Key_F8,
    Key_F9,
    Key_F10,
    Key_Invalid,
    Key_Invalid, // 70
    Key_Home,
    Key_Up,
    Key_PageUp,
    Key_Invalid,
    Key_Left,
    Key_Invalid,
    Key_Right, // 77
    Key_Invalid,
    Key_End,
    Key_Down, // 80
    Key_PageDown,
    Key_Invalid,
    Key_Delete, // 83
    Key_Invalid,
    Key_Invalid,
    Key_Backslash,
    Key_F11,
    Key_F12,
    Key_Invalid,
    Key_Invalid,
    Key_Logo,
};

static KeyCode shifted_key_map[0x100] = {
    Key_Invalid,
    Key_Escape,
    Key_ExclamationPoint,
    Key_AtSign,
    Key_Hashtag,
    Key_Dollar,
    Key_Percent,
    Key_Circumflex,
    Key_Ampersand,
    Key_Asterisk,
    Key_LeftParen,
    Key_RightParen,
    Key_Underscore,
    Key_Plus,
    Key_Backspace,
    Key_Tab,
    Key_Q,
    Key_W,
    Key_E,
    Key_R,
    Key_T,
    Key_Y,
    Key_U,
    Key_I,
    Key_O,
    Key_P,
    Key_LeftBrace,
    Key_RightBrace,
    Key_Return,
    Key_Control,
    Key_A,
    Key_S,
    Key_D,
    Key_F,
    Key_G,
    Key_H,
    Key_J,
    Key_K,
    Key_L,
    Key_Colon,
    Key_DoubleQuote,
    Key_Tilde,
    Key_LeftShift, // 42
    Key_Pipe,
    Key_Z,
    Key_X,
    Key_C,
    Key_V,
    Key_B,
    Key_N,
    Key_M,
    Key_LessThan,
    Key_GreaterThan,
    Key_QuestionMark,
    Key_RightShift, // 54
    Key_Invalid,
    Key_Alt,
    Key_Space,   // 57
    Key_Invalid, // 58
    Key_F1,
    Key_F2,
    Key_F3,
    Key_F4,
    Key_F5,
    Key_F6,
    Key_F7,
    Key_F8,
    Key_F9,
    Key_F10,
    Key_Invalid,
    Key_Invalid, // 70
    Key_Home,
    Key_Up,
    Key_PageUp,
    Key_Invalid,
    Key_Left,
    Key_Invalid,
    Key_Right, // 77
    Key_Invalid,
    Key_End,
    Key_Down, // 80
    Key_PageDown,
    Key_Invalid,
    Key_Delete, // 83
    Key_Invalid,
    Key_Invalid,
    Key_Pipe,
    Key_F11,
    Key_F12,
    Key_Invalid,
    Key_Invalid,
    Key_Logo,
};

void KeyboardDevice::key_state_changed(u8 raw, bool pressed)
{
    Event event;
    event.key = (m_modifiers & Mod_Shift) ? shifted_key_map[raw] : unshifted_key_map[raw];
    event.character = (m_modifiers & Mod_Shift) ? shift_map[raw] : map[raw];
    event.flags = m_modifiers;
    if (pressed)
        event.flags |= Is_Press;
    if (m_client)
        m_client->on_key_pressed(event);
    m_queue.enqueue(event);
}

void KeyboardDevice::handle_irq()
{
    for (;;) {
        u8 status = IO::in8(I8042_STATUS);
        if (!(((status & I8042_WHICH_BUFFER) == I8042_KEYBOARD_BUFFER) && (status & I8042_BUFFER_FULL)))
            return;
        u8 raw = IO::in8(I8042_BUFFER);
        u8 ch = raw & 0x7f;
        bool pressed = !(raw & 0x80);

#ifdef KEYBOARD_DEBUG
        dbgprintf("Keyboard::handle_irq: %b %s\n", ch, pressed ? "down" : "up");
#endif
        switch (ch) {
        case 0x38:
            update_modifier(Mod_Alt, pressed);
            break;
        case 0x1d:
            update_modifier(Mod_Ctrl, pressed);
            break;
        case 0x5b:
            update_modifier(Mod_Logo, pressed);
            break;
        case 0x2a:
        case 0x36:
            update_modifier(Mod_Shift, pressed);
            break;
        }
        switch (ch) {
        case I8042_ACK:
            break;
        default:
            if (m_modifiers & Mod_Alt) {
                switch (map[ch]) {
                case '1':
                case '2':
                case '3':
                case '4':
                    VirtualConsole::switch_to(map[ch] - '0' - 1);
                    break;
                default:
                    key_state_changed(ch, pressed);
                    break;
                }
            } else {
                key_state_changed(ch, pressed);
            }
        }
    }
}

static KeyboardDevice* s_the;

KeyboardDevice& KeyboardDevice::the()
{
    ASSERT(s_the);
    return *s_the;
}

KeyboardDevice::KeyboardDevice()
    : IRQHandler(IRQ_KEYBOARD)
    , CharacterDevice(85, 1)
{
    s_the = this;

    // Empty the buffer of any pending data.
    // I don't care what you've been pressing until now!
    while (IO::in8(I8042_STATUS) & I8042_BUFFER_FULL)
        IO::in8(I8042_BUFFER);

    enable_irq();
}

KeyboardDevice::~KeyboardDevice()
{
}

bool KeyboardDevice::can_read(FileDescription&) const
{
    return !m_queue.is_empty();
}

ssize_t KeyboardDevice::read(FileDescription&, u8* buffer, ssize_t size)
{
    ssize_t nread = 0;
    while (nread < size) {
        if (m_queue.is_empty())
            break;
        // Don't return partial data frames.
        if ((size - nread) < (ssize_t)sizeof(Event))
            break;
        auto event = m_queue.dequeue();
        memcpy(buffer, &event, sizeof(Event));
        nread += sizeof(Event);
    }
    return nread;
}

ssize_t KeyboardDevice::write(FileDescription&, const u8*, ssize_t)
{
    return 0;
}

KeyboardClient::~KeyboardClient()
{
}
